青藏高原强震活动诱发因素研究

印度板块-欧亚板块碰撞导致的构造应力累积是引发青藏高原地震的动力机制,但地震是开放系统的产物,通过对青藏高原强震发震时间与太阳黑子活动周期、白赤交角变化周期、高原冰川消融时间呼应关系的分析,探讨了青藏高原近期的强震活动幕和特大地震活动趋势。研究结果表明,强震的发震时间大多处于太阳黑子数量由峰值到谷值的转化阶段和白赤交角由极大值至极小值的相位时段;冰川消融对地壳表层负载平衡的破坏作用导致青藏高原最近5次8.0级以上强震中除1950年察隅地震之外其余的4次特大地震均发生于春夏之交和秋冬之交的冰雪冻融过渡时期。结合青藏高原地震的天文背景、地文因素及地震的空间位置迁移规律,预测2025-2032年青藏高原巴颜喀喇断块可能迎来一次地震活动丛集期,2025年前后在该次级断块偏西区域可能发生8.0级左右的特大地震。

Astronomic background of global huge earthquakes at beginning of 21st century

Since the beginning of the 21st century,major earthquakes have frequently occurred worldwide.To explore the impact of astronomical factors on earthquakes,in this study,the statistical analysis method of correlation is used to systematically analyze the effects of astronomical factors,such as solar activity,Earth’s rotation,lunar declination angle,celestial tidal force,and other phenomena on M≥8 global earthquakes at the beginning of the 21st century.With regard to solar activity,this study focuses on the analysis of the 11-year and century cycles of solar activity.The causal relationship of the Earth’s rotation is not obvious in this work and previous works;in contrast,the valley period of the solar activity century cycle may be an important astronomical factor leading to the frequent occurrence of global earthquakes at the beginning of the 21st century.This topic warrants further study.

Correlation of eco-hydrographic benefit and height increment of Robinia pseudoacacia stand with climatic environmental factors in Yellow River Delta Wetland of China

The relationship between eco-hydrographic benefit of forest vegetation and climatic environmental factors is one of the focuses in the research on environmental protection and ecosystem countermeasures in Wetland. The runoff, sediment and soil moisture rate dynamics in Robinia pseudoacacia plantation and its clearcut area were investigated in the natural runoff experiment plots in Yellow River Delta Wet- land, Shandong Province, China. The correlation of height increment ofR. pseudoacacia with nine climate factors such as light, water, heat, etc. was analyzed by stepwise regression analysis. The results showed that the amounts of runoff and sediment in clearcut area of R. pseudoacacia were 53.9%-150.8% and 172.8%-387.1% higher than that in Robinia pseudoacacia plantation, respectively. The runoff peak value in R. pseudoacacia stand was obviously lower than that in clerarcut area, meantime, the occurrence of runoffpeak in R. pseudoacacia stand was 25 min later than in its clerarcut area. The soil moisture rates in R. pseudoacacia stand and its clearcut varied periodically with annual rainfall precipitation in both dry season and humid season. The annual mean soil moisture rate in R. pseudoacacia stand was 23.3%-25.6% higher than that in its clearcut area. Meanwhile, a regression model reflecting the correlation between the height increment of R. pseudoacacia and climatic factors was developed by stepwise regression procedure method. It showed that the light was the most important factor for the height increment ofR. pseudoacacia, followed by water and heat factors.

Influencing factors of infrared surveying in roadway

The main factors that affect infrared surveying in roadway include that property of rock, electromechanical equipments running, environmental temperature, hydrogeology and support material etc. This paper sums up the expression features of these disturbing factor through theoretical analysis and actual measurement contrasts and considers that some tunnel section does not suit to go on infrared survey, for instance, soft rock meets water to expanse, and surround rock has obviously pouring water. The basic methods had made evading disturbing of electromechanical equipments, environmental temperature and protect material etc to become possible. It is helpful that offers infrared surveying technical service for production safety better in roadway.

The enrichment characteristics and geological controlling factors of coalbed methane occurrence in Laochang area, Yunnan Province

The enriched characters of methane content in the main coal seam of Yunnan＇s Laochang coal mine was analyzed through combined with the geologic conditions of the research area： structure type, hydrogeology condition, coal reservoir＇s macerals, ash, water content, and so on. The geology factors of controlling gas in Laochang coal mine were illustrated; and the different geology models of controlling gas of geologic condition coupling were posed. Research shows that, in the region, the methane contents of the main coal seams decrease gradually from middle to all around it; the northeast and southeast is higher than the west. In the local area, the methane content of anticline axis is higher, and the gas content is reduced to both wings and plunging crown. On macroscopic view, the distribution of methane content in coal-beds was controlled by structural type. On microscopic view, the methane content in coal-beds is mainly involved in coal reservoir＇s macerals, ash content, and water content. The enriched characters of CBM in the research area are mainly the result of structure-hydrogeology-petrophysics coupling controls of CBM. On the basis of above analysis, according to the distribution character of methane content in coalbeds, the research area was divided into low gas area, middle gas area, and high gas area.